Patina on bronze

Jewelry Discussion
1

Hi All, I have been trying to put a ferric nitrate (red/brown) patina
on a bronze piece and have trouble in that I get a mottled
appearance. I’ve cleaned the surface and used distilled water in my
solutions. What can I do? Thanks in advance. Richard Malenky

2

I think if you heat the piece lightly with torch, around 200 degrees
F or let it sit in a window in direct sunlight for an hour or so,
you’ll have much better results. You could also increase the strength
of your solution. The piece should be warm enough that you can see
the soln. slowly steaming off. If you see it instantly boiling off
when you apply the soln., it is too hot and may not fully react.

Give it a shot and see if it helps.

Mike Dibble
Black Horse Design
www.black-horse-design.com

3 
Hi All, I have been trying to put a ferric nitrate (red/brown) patina
on a bronze piece and have trouble in that I get a mottled
appearance.   I've cleaned the surface and used distilled water in my
solutions.

I work on bronze statuary and Ferric Nitrate is put on HOT. If you
want it red, add a couple of crystals of Sodium Thio Sulphate (Black
and white photo fixer). for the most even and smooth application,
try putting it on with an air brush (harbor freight has them on sale
often for under $5.00). Be sure to rinse well when finished as FN
eats the steel parts on the airbrush (the cap holding the bottle of
paint/solution). To me spots are of too cool of metal and/or
improper applications technique (sometimes one wants spots…). So
you might consider the air brush and for a redder color, the Sodium
TS.

John Dach